Time element relay



f 1938. ,F. a. HITCHCOCK 2,132,109

' TIME ELEMENT RELAY Filed March 16, 1955 3 Sheets-Sheet 1 FIG-1.

/7)P2;VENTOR BY J A5 WW5 MM @afl,

ATTORNEY Oct. 4, 1938. F. a. HrrcHcocK TIME ELEMENT RELAY Filed March 16, 1935 3 Sheets-Sheet 2 Fig.3;

INVENTOR BY jg l\bRN EY 'Oct. 4, 1938. F. B. HITCHCOCK TIME ELEMENT RELAY Filed March 16, 1935 3 Sheets-Sheet 3 QM WMA sn 3 ma BY &

BE UA r I n 1 il :35 k mm X Judi ATTORNEY 9 Patented Oct. 4, 1938 TILIE ELEMENT RELAY Forest B. Hitchcock, Greece, N. Y., assignor to General Railway Signal Company, Rochester, N.

Application March 16,

13 Claims.

This invention relates in general to relays, and has more particular reference to a time element relay having principles of operation particularly adapted for railway use.

In many instances, it is desirable to have a relay which controls circuits in a manner to measure a predetermined time following its own energization. In some cases where relays of this type are employed, such predetermined times may be of such long duration as to render it impossible to obtain the desired delay with the usual means of delaying an electro-magnetic structure, thereby making itnecessary to resort to mechanical delay devices which may not always operate on the side of safety as required in railway practice.

One object of the present invention is to provide an electro-magnetic structure which will measure a prolonged predetermined period of time in an accurate and reliable manner, in such a way that any momentary failure of energy will cause the device to immediately restore to normal.

Another object of the invention is to provide that the restoration to normal of the device upon its deenergization shall be mechanically independent of its operating means.

With the above and other objects in mind, it is proposed to provide a time element relay of a type that has been conveniently termed a magnetic thread screw timer. More specifically, a cylinder like armature having threads thereon of magnetic material is caused to be rotated at a predetermined'rate between two magnetized pole pieces which have extending portions there- 35 on to conform with the threads of the cylinder like armature, but which do not mechanically come into contact with the armature. The movement of the cylinder like armature in a longitudinal direction is wholly dependent upon the magnetic pull continuously exerted upon the armature to maintain the threads of the armature in alinement with the threads of the pole pieces. It

can thus be readily seen that the cylinder like armature may be biased in one direction by suitable means such as gravity, and be caused to be actuated in the opposite direction only when the pole pieces are suitably energized and the armature rotated in the proper direction, so that the deenergization of such pole pieces causes the immediate restoration of the armature to its biased position because of the absence of any mechanical contact between the armature and pole pieces.

Another object of the invention is to provide that the controlled circuits may be opened and/or 1935, Serial No. 11,517

closed both at the beginning of operation of the relay and at the end of the operation.

Another object of the invention is to provide that the relay may be employed in connection with either alternating or direct currents as explained more specifically hereinafter.

Other objects, purposes and characteristic features of the present invention will be in part obvious from the accompanying drawings, and in part pointed out as the description of the invention progresses.

In describing the invention in detail, reference will be made to the accompanying drawings, in which like reference characters designate corresponding parts throughout the several views, and in which:-

Fig. 1 is a sectional elevation of one form of the present invention as taken on lines |l of Fig. 2;

Fig. 2 is a sectional view of the present invention as taken upon lines 2-2 of Fig. 1;

Fig. 3 is a modified form of the present invention illustrating a structure which is adaptable for use in connection with direct current instead of with alternating current as shown in Fig. 1;

Fig. 4 is a diagrammatic illustration of one manner in which the present invention may be employed to control circuits in a manner to measure predetermined times; and

Fig. 5 is a diagrammatic illustration of another circuit arrangement in which the present invention may be employed to control time delayed circuits.

With reference to Fig. 1 of the accompanying drawings, a casing 5 is employed to enclose the operating structure of the timing device having a dividing portion 6 to separate the driving mechanism and the operating compartment including contacts and operating coils. The driving compartment of the casing 5 is enclosed by a cover I and includes a self-starting synchronous motor M which drives the shaft |2 through pinion 8, gear 9, bevel pinion I0 and bevel gear I I.

This shaft I2 is of non-magnetic material and extends between the lower cover 1 and the upper cover l3 having suitable bearings in the cover l3 and the dividing section 6. The lower cover 1 is provided with a suitable end thrust bearing l4 constructed to provide a minimum amount of friction by using a ball bearing as shown, or a suitable means as may be desired in practice.

The shaft 12 has a key-way in which a key l5 may freely slide in a longitudinal direction but is attached to the helical armature I6 by a suitable set screw IT. The armature i6 is of magv netic material and has a cylinder like shape with illustrated in Fig. 2 by insulating portions 2!, 22, '23 and 24.

The pole pieces 58 and i9 have their pole faces arranged in a thread like manner so that the extending portions conform'with and follow adjacent'the threads of the armature E6 to thereby form a magnetic path from one pole piece to the other by the way of the threads upon the armature IS in a manner that the lowest possible reluctance of this magnetic path will be when the threads of the armature and the pole pieces coincide.

The pole pieces .18 and I9 have mounted thereon suitable coils and 26 which are energizable in series in a manner 'to cause magnetic flux to pass from pole piece I8 to pole piece i9 or vice versa depending upon the polarity applied to the coils. The circular structure 2!! provides two return paths for the magnetic circuit so that the flux divides substantially equally between such return paths thereby making it possible to provide a greater cross sectional area in the pole pieces then in the circular portions 20 and still retain the same flux density.

It may be noted here, that the armature l6 may have its cylinder like portion of non-magnetic light weight material, such as aluminum for example, provided that the threads are of magnetic material. This arrangement may be desirable in order to reduce the weight of the armature as much as possible to thereby necessitate a smaller degree of energization of the operating coils 25 and 26.

In the operating compartment of the casing, suitable contact blocks are located. More specifically, the contact blocks may be radially located about the shaft l2 both on the lower dividing section 6 and on the upper cover 13 so that a large number of contacts may be operated by the armature 16. The disclosure of Fig. 1 illustrates one contact block 2'! on the dividing section 6 provided with front contact 28, back contact 29 and movable contact 3|]. The movable contact 30 is normally biased to a front contacting position but when the operating coils 25 and 2B are de-energized the armature it assumes its downwardly biased position (biased by gravity) which causes the movable contact 30 to engage the back contact 29.

Contact blocks 3| and 32 are illustrated as mounted on the cover plate l3. Contact block 3| has back contact 33, front contact 34, movable contact 35; while contact block 32 has back contact 36, front contact 31, movable contact 38. The movable contacts 35 and 38 are normally biased to make contact'with their back points 33 and 36 respectively, but when the armature l6 has beenoperated to its upper extreme position the movable contacts 35 and 38 are caused to make contact with their front points 34 and 31 respectively.

tacts 39 and 40 close simultaneously causing the operating coils 25 and 26 to be energized at the same time that motor M is energized.

The self-starting synchronous motor M starts almost instantly and operates at a predetermined speed in accordance with the frequency of the alternating current which rotates the shaft I2 at a predetermined reduced rate. This causes the armature IE to climb the magnetic thread at a predetermined rate opening back contacts 29-30 and closing front contacts 28-40 at the very beginning of its operation while at the end of its operation back contacts 33-35 and 3t-38 are broken and front contacts 34-35 and 3'l-38 r are closed. The de-energization of the control relay Ccauses the armature iii to return almost instantly to its normal position.

It is to be noted that the gearing ratio between the synchronous motor M and the shaft i2 will be wholly dependent on the frequency of the alternating current source and upon the time period desired to be measured. It should also be noted that the battery source 52 may have substituted therefore suitable rectifiers so as to de rive the energy for coils 25 and 26 from the alternating current source 4 l With reference to Fig. 3, the driving compartment of the structure of Fig. 1 has been shown as provided with a suitable fly-ball governor connected through bevel pinion A l to the bevel gear 5 I of Fig. 1. This fly-ball governor includes balls 43 rotated at a rate dependent upon the speed of operation of the shaft I2 as operated by the gear H which compresses a spring 25 in accordance therewith. As the spring 45 is compressed, a rotating braking surface 46 is drawn toward and contacts a fixed braking surface 41. When the speed increases to a predetermined point the friction between 46 and ti prevents further increase, so that the speed of rotation of the shaft I2 is maintained at a substantially constant rate as determined by the setting of this governor.

The addition of this governor is particularly desirable, as the motor M is contemplated as being of the direct current type controlled from the suitable battery source 42 through the control relay C by contact 40. The operating coils 25 and 26 of the relay are controlled from the same battery source 42 as shown in Fig. 1. This arrangement of the timing device and its control in .accordance with the present invention is desirable when direct current is employed, because it is well understood that the voltage of a direct current source may vary due to the different degree of charge of a battery source, or due variations in current by reason of changes in temperature thus changing the resistance of the operating coils of the motor as well as the resistance of the lead wires. 7

In this arrangement, the normal voltage applied to the direct current motor M should be of a sufficient value that the governor is effective in determining the speed of operation of the shaft [2, so that a change in voltage either up or down will still allow the governor to dominate and in accordance with its setting.

Fig. '4 shows in a diagrammatic manner the timing device 'of the present invention as controlling a suitable circuit indicated on the drawings by the legend circuits to be controlled.

This figure is intended to illustrate that the motor M may be de-energized at the end of the operating stroke of the armature [6 by the opening of its contacts 33--35, and to also illustrate that the timing device may be so controlled as to fail to be operated unless it is in its normal position. This latter feature is accomplished by.

providing that'the control relay C is capable of being picked up by its control means, such as the manually operable lever L, unless contacts 29-30 are closed with the armature H5 in a normal deenergized position. Once the relay C is picked up, it is maintained picked up until the lever L is restored to normal by a stick circuit including its front contact 48. The operating coils 25and ,26 of the timer are controlled by contact 39 of relay C from suitable direct current source such as battery 42 which has been merely indicated by symbols in the figure, while contact 40 of relay C is employed to control the self-starting synchronous motor M as shown in Fig. 1.

Fig. 4 illustrates the manner in which circuits may be opened and/0r closed at the end of the operation of the armature l6 (by contacts 36, 31 and 38), but this relay timing device of the present invention may also be employed to close a circuit dependent only upon the complete operation of the armature 16 to an operating position and then returned to its normal position as shown in Fig. 5 of the accompanying drawings.

In this Fig. 5, the control relay C is illustrated as capable of being picked up by lever L only when a relay 2C is de-energized closing its back contact 49. The relay 2C is always de-energized picked up and stuck up through its contact 48,

which energizes the operating coils 25 and 25 through contacts 52 and 53 of relays 2C and C respectively, and also energizes the self-starting synchronous motor M through contacts 54 and 55. The armature I6 is operated after a predetermined time to close contacts 3435 which picks up relay 2C. The picking up of the contacts of relay 2C closes its stick circuit including front contact 5| of relay C and its own front contact 50. The opening of back contact 52 and back contact 54 de-energizes the operating windings 25 and 26 and the windings of the motor M so that the armature l6 almost instantly assumes its normal position and the motor stops operating.

As soon as the armature I6 assumes its normal position the circuit to be controlled as indicated by a legend on the drawings is closed by reason of the closure of contacts 29-30 and front contact 58 of relay 2C. Relay C and 2C remain picked up so long as the lever L remains in an operated position, but, when the lever L is restored to its normal position, the relays C and 2C are immediately de-energized. Thus, the circuit to be controlled is closed a predetermined time after the operation of the lever L as measured by the operation of the armature I6 and the return of such armature to its normal position.

Having described a relay timing device and some of its control circuits as one specific embodiment of the present invention, it is desired to be understood that this form is selected to facilitate in the disclosure of the invention rather than to limit the number of forms which it may assume; and, it is to be further understood that various modifications, adaptations and alterations may be applied to the specific form shown to meet the requirements of practice, without in any manner departing from the spirit or scope of the present invention except as limited by the appended claims.

What I claim is:

1. In a power operated time element device for operating contacts, pole pieces having helical threads, a magnetic thread screw armature coacting with said pole pieces to give relative movement when driven, a synchronous motor for driving said armature, contacts operated by the relative movement of said armature, whereby said contacts are operated within a predetermined time.

2. In a power operated time element device for operating contacts; pole pieces having helical threads; an armature having helical threads and associated with said pole pieces but mechanically free from said pole pieces, said armature coacting to give relative movement when said pole pieces are energized and said armature is driven;

magnetizing said pole pieces; and contacts operated by the completion of the relative movement of said armature; whereby said contacts are operated a predetermined time after said pole pieces are magnetized.

3. In a power operated time contactor, a rotatable armature having threads thereon of magnetic material, said armature being movable longitudinally, pole pieces located around said armature, said pole pieces having threads thereon but mechanically free from said threads on said armature, means for magnetizing said pole pieces, means for rotating said armature, whereby said armature moves longitudinally between said pole pieces, and contact means operated by said armature.

4. In a power operated time contactor, a threaded armature mounted so as to be rotatable and movable longitudinally, said armature being biased in one longitudinal direction, threaded pole pieces associated with said thread armature but mechanically independent therefrom, means for rotating said armature, means energizing said pole pieces, whereby said armature moves longitudinally in a direction opposite to its bias, and whereby the de-energization of said pole pieces allows said armature to freely return to its biased position, and contact means operatively connected to said armature.

5. In a power operated timing device, a threaded armature mounted so as to be rotatable and movable longitudinally, said armature being biased in one longitudinal .direction, threaded pole pieces-associated with said thread armature but mechanically independent therefrom, means for rotating said armature, means energizing'said pole pieces, contacts operated by said armature, and means controlling said energizing means.

6. In a power operated time measuring device, a threaded armature mounted so as to be rotatable and movable longitudinally, said armature being biased in one longitudinal direction, threaded pole pieces associated with said thread armature but mechanically independent therefrom, a self-starting synchronous motor for rotating said threaded armature in a direction to longitudinally move said armature away from its biased position whensaid threads are rendered effective by the magnetizing of said pole pieces,

contacts operated by said armature when said armature is in a position opposite to its biased position,v means for simultaneously rendering said synchronous motor energized and said threads effectively magnetized, and means for deenergizing said motor when said armature reaches said opposite position. 7

7. In a power operated time contactor, a vertical rotatable shaft of non-magnetic material, an armature of magnetic material having threads thereon and located on said shaft so as to be slidable longitudinally but non-rotatable thereon, means for rotating said shaft at a predetermined rate, pole pieces adjacent said armature and provided with threads opposite the threads of said armature but mechanically independent therefrom, and means for energizing said pole pieces to cause magnetic flux to pass between said pole pieces by the way of said armature, whereby said armature moves upwardly on said shaft.

8. In a time ,measuring circuit control mechanism, a stationary helical field, a rotatable helical armature coacting with said field and longitudinally movable, means for at times energizing said field whereby magnetic threads provide the tractive force for longitudinally moving said armature when it is rotated, a substantially constant speed driving means for rotating said armature, and contacts operated by the longitudinal movement of said armature.

9. In a power driven time contactor, pole pieces having threads thereon, means for magnetizing said pole pieces, an armature having threads thereon coacting with the threads on said pole pieces only by magnetic traction to thereby give relative movement to the armature when itis rotated, a substantially constant speed driving motor for rotating said armature, means for initiating operation of said motor, and contacts operated by a predetermined movement of said armature to thereby be operated a predetermined time after the initiation of armature rotation.

10. In a power driven time contactor; a threadedrarmature mounted so as to be rotatable and movable longitudinally, said armature being biased by gravity in one longitudinal direction; threaded pole pieces associated with said armature but mechanically independent therefrom; means for at times rotating said armature for a predetermined period of time; means for at times, energizing said pole pieces to cause magnetic flux to pass between the threads of said pole pieces to produce tractive effort onsaid armature so as to move in a longitudinal direction against its bias when rotated; and contacts operated by the longitudinal movement of said armature at the extremities of such movement.

11. In a time measuring device; a threaded armature mounted so as to be rotatable and movable longitudinally, said armature being biased by gravity in one longitudinal direction; threaded pole pieces associated with said thread armature but mechanically independent therefrom; a

self-starting synchronous motor for'rotating said for deenergizing said synchronous motor when said armature reaches said opposite position without demagnetizing said pole pieces.

12. In a power operated time measuring device; a threaded armature mounted so as to be rotatable and movable longitudinally, said armature being biased by gravity in one longitudinal direction; threaded pole pieces associated with said threaded armature but mechanically independent therefrom; a substantially constant speed motor for rotating said threaded armature in a direction to longitudinally move said armature away from its biased position when said threads are rendered effective by the magnetizing of said pole pieces; contacts operated by said armature when said armature is in a position opposite to its biased position; control means effective, when operated, for simultaneously rendering said synchronous motor energized and said threads effectively magnetized; and means for deenergizing said motorwhen said armature reaches said opposite position without demagnetizing said pole pieces, said means acting only while said control means is in an operated condition.

13. In a power operated time measuring device; a threaded armature mounted so as to be rotatable and movable longitudinally, said armature beingbiased in one longitudinal direction; threaded pole pieces associated with said threaded armature but mechanically independent therefrom; a self-starting synchronous motor for rotating said threaded armature in a direction to longitudinally move said armature away from its biased position when said threads are rendered efiective by the magnetizing of said pole pieces; contacts operated by said armature when said armature is in a position opposite to its biased position; means for simultaneously rendering said synchronous motor energized and said threads effectively magnetized; and means including said contacts for deenergizing said motor and for demagnetizing said pole pieces when said armature reaches said opposite position; and a circuit closed only after said armature has been operated to said opposite position and returned to its normal biased position.

FOREST B. HITCHCOCK. 

